This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. To evaluate the role of the lateral prefrontal cortex in modulating emotion and in mediating the behavioral and [unreadable] physiological characteristics of the anxious endophenotype.[unreadable] [unreadable] High levels of freezing (behavioral inhibition) are traits associated with the anxious endophenotype. We have [unreadable] defined three groups of rhesus monkeys exhibiting low, medium, and high levels of freezing behavior. We are [unreadable] further testing these animals on other behavioral and physiological measures. We are using PET and MRI [unreadable] technology to examine brain activity and structure. These measures will help us evaluate specific contributions of [unreadable] the lateral prefrontal cortex (LPFC) in emotion processing in rhesus monkeys. This research used WNPRC Animal [unreadable] Services, Surgery, and Library and Information Systems Services.